Issue Archive

This week's Question: This month, the Federal Aviation Administration proposed long-awaited rules on the commercial use of small drones, requiring operators to be certified, fly only during daylight, and keep their aircraft in sight. The ruling, for now, prevents drones from being used for a range of possible other commercial uses, including crop inspection and package delivery. What do you think? Are FAA drone rules too restrictive?

Harvard School of Engineering and Applied Sciences researchers developed an ultra-thin, completely flat lens made of a glass substrate and tiny, light-concentrating silicon antennas. Color correction is achieved in the single, miniaturized device.Light shining on the "achromatic metasurface" lens bends instantaneously, rather than gradually, while passing through. The bending effects can be designed in advance, by an algorithm, and fine-tuned to fit specific applications.With no need to increase the lens thickness and footprint, the optical technology compensates for wavelength differences and produces a consistent effect — for example, deflecting three beams of different colors by the same angle, or focusing those colors on a single spot. The model uses a dielectric material rather than a metal for the nanoantennas, a change which greatly improves its efficiency and, combined with a new design approach, enables operation over a broad range of wavelengths.The technology could be used to create new miniature optical communications devices, compact cameras, and imaging technologies.SourceLearn about the design of a GRadient INdex (GRIN) lens.

A breakthrough propulsion technology to provide greener air transport could be developed after the underlying engineering was declared a success. Six universities and two research organizations from across the EU demonstrated the scientific feasibility of a novel propulsion method that overcomes the main limitations of traditional systems related to jet deflection exhausts.

NASA is working with CUBRC Inc. of Buffalo, NY to design, build, and test 2% scale models of the Space Launch System (SLS) propulsion system. Models include two five-segment solid rocket boosters and four core stage RS-25 engines, and a 2% scale model of the entire rocket. The models are fired for short durations of about 50-150 milliseconds per test.

Researchers are investigating how unmanned aerial vehicles (UAVs) can be used commercially in agriculture. Their size, cost and capabilities make UAVs useful for a wide range of jobs. Mississippi State University researchers are already using these vehicles, and many others are examining their potential applications, including flying a camera on a drone to get instant aerial views of research fields.
A flyover could identify problem spots in extremely large fields, and then researchers, crop consultants, or farmers could go to the identified areas and examine them carefully to make proper diagnoses. The information gathered by soil-moisture sensors could be compared to the information that could be gathered by drones.
Technology already exists to allow producers to make very specific chemical applications to their fields with farm equipment. UAVs can help them target these applications even more precisely.
Source:

To realize the "Internet of things” — the idea that all parts of the human environment, from kitchen appliances to industrial equipment, could be equipped with sensors and processors that exchange data — transmitters must be energy-efficient enough to last for months.
A group researchers at the Massachusetts Institute of Technology (MIT) have developed a new transmitter design that reduces off-state leakage 100-fold. The design provides adequate power for Bluetooth transmission, or for the longer-range 802.15.4 wireless-communication protocol.
While semiconductors are not naturally very good conductors, neither are they perfect insulators. Even when no charge is applied to the gate, some current still leaks across the transistor.
The leakage is reduced by applying a negative charge to the gate when the transmitter is idle. The charge drives electrons away from the electrical leads, making the semiconductor a much better insulator.
In tests conducted on a prototype chip fabricated through the Taiwan Semiconductor Manufacturing Company’s research program, the MIT researchers found that their circuit spent only 20 picowatts of power to save 10,000 picowatts in leakage.
To generate the negative charge efficiently, the MIT researchers use a circuit known as a charge pump, which is a small network of capacitors — electronic components that can store charge — and switches. When the charge pump is exposed to the voltage that drives the chip, charge builds up in one of the capacitors. Throwing one of the switches connects the positive end of the capacitor to the ground, causing a current to flow out the other end.
Source
Also: Read other Electronics tech briefs.

This week's Question: Mars One, a group that plans to send humans on a one-way trip to Mars, has narrowed its application pool from 200,000 to 100. The finalists will spend the next decade in training, including team-building exercises and isolation. The goal of the Netherlands-based non-profit is to start a permanent colony on Mars. If the mission is launched, the colonists will never return to Earth. One mission is scheduled to launch in 2025, followed by another every two years. What do you think? Would you take a one-way trip to Mars?

Question of the Week

This week's Question: This month, the Federal Aviation Administration proposed long-awaited rules on the commercial use of small drones, requiring operators to be certified, fly only during daylight, and keep their aircraft in sight. The ruling,...